Healthy Buildings and Indoor Air Quality: Insights from Dr. Joseph Allen
If you enrolled in Dr. Joseph Allen’s healthy buildings course at Harvard this term, your first stop would be the campus statue of Alice Hamilton. Allen considers Hamilton a role model—a trailblazer in industrial toxicology who uncovered that early 20th-century workers were falling ill due to inhaling lead, not poor hygiene. Her research directly improved worker safety and helped shape regulations requiring employers to implement protective measures.
Dr. Allen, a professor at Harvard T.H. Chan School of Public Health, head of Harvard’s Healthy Buildings Program, and author of the best-selling Healthy Buildings, is a scientist who blends research with advocacy. Throughout his career, he has worked to improve indoor environments for people everywhere. Beyond publishing in scientific journals, he focuses on translating research into practical approaches that make buildings healthier in real-world settings.
At IWBI’s WELL Summit in New York City, Allen joined IWBI President and CEO Rachel Hodgdon for a lively discussion on the future of healthy buildings. Below are key takeaways from their conversation.
When asked about the current state of the healthy building movement, Allen noted growing institutional momentum and leadership from non-governmental organizations. He highlighted milestones such as the first indoor air quality event at the United Nations during Climate Week, the launch of the Global Commission on Healthy Indoor Air, and new leadership at ASHRAE emphasizing health-focused building standards. He also emphasized that private-sector organizations are increasingly taking action.
Allen’s recent research on the Los Angeles wildfires examined how long harmful pollutants persist in the air, including indoors—an area previously under-studied. His findings revealed that toxic nanoparticles, including lead and hexavalent chromium, remained present for months, often at higher concentrations indoors. These particles can penetrate the body, cross the blood-brain barrier, and impact multiple organs and systems.
Although much of Allen’s work appears in academic publications, he also conducts research funded by corporations. He explained that industry partnerships can accelerate scientific discovery and broaden the impact of research outcomes.
Hodgdon referenced Allen’s COGfx study, published in 2016, which demonstrated that improved indoor air quality—lower CO₂ and VOC levels—nearly doubled cognitive performance compared to conventional office environments. Allen recalled releasing the study at Greenbuild and promoting it globally to make the findings more relatable and impactful.
Allen also advised on indoor air quality systems at JPMorgan’s new headquarters in New York City, featuring enhanced ventilation, filtration, and real-time monitoring in line with WELL recommendations. JPMorgan adopted many of these measures more than a decade ago, despite skepticism at the time. Today, the improvements deliver significant financial and organizational benefits, including better hiring, retention, and employee productivity.
Recently, Allen’s team has been using artificial intelligence to move from identifying problems to testing solutions. They created a privacy-safe digital model of the U.S. population to identify groups most at risk from poor indoor air. Their findings show that young children in older homes built before the 1970s face the greatest exposure risk due to lead-based paint. The team is also modeling wildfire scenarios to evaluate how better building design could have reduced exposure during the Los Angeles fires.
When asked what will become standard practice in the next decade, Allen predicted widespread adoption of real-time indoor air quality sensors in homes and buildings. He emphasized that monitoring is essential to prevention: “You can’t manage what you don’t measure.”
Allen also shared practical advice for improving indoor air at home, including enhancing ventilation and filtration, reducing exposure to persistent chemicals, and focusing on bedroom air quality, given the time people spend sleeping. He described ventilation and filtration as fundamental pillars of public health.
Ultimately, healthier indoor environments can improve well-being for people everywhere, making better buildings a universal benefit.
Dr. Allen, a professor at Harvard T.H. Chan School of Public Health, head of Harvard’s Healthy Buildings Program, and author of the best-selling Healthy Buildings, is a scientist who blends research with advocacy. Throughout his career, he has worked to improve indoor environments for people everywhere. Beyond publishing in scientific journals, he focuses on translating research into practical approaches that make buildings healthier in real-world settings.
At IWBI’s WELL Summit in New York City, Allen joined IWBI President and CEO Rachel Hodgdon for a lively discussion on the future of healthy buildings. Below are key takeaways from their conversation.
When asked about the current state of the healthy building movement, Allen noted growing institutional momentum and leadership from non-governmental organizations. He highlighted milestones such as the first indoor air quality event at the United Nations during Climate Week, the launch of the Global Commission on Healthy Indoor Air, and new leadership at ASHRAE emphasizing health-focused building standards. He also emphasized that private-sector organizations are increasingly taking action.
Allen’s recent research on the Los Angeles wildfires examined how long harmful pollutants persist in the air, including indoors—an area previously under-studied. His findings revealed that toxic nanoparticles, including lead and hexavalent chromium, remained present for months, often at higher concentrations indoors. These particles can penetrate the body, cross the blood-brain barrier, and impact multiple organs and systems.
Although much of Allen’s work appears in academic publications, he also conducts research funded by corporations. He explained that industry partnerships can accelerate scientific discovery and broaden the impact of research outcomes.
Hodgdon referenced Allen’s COGfx study, published in 2016, which demonstrated that improved indoor air quality—lower CO₂ and VOC levels—nearly doubled cognitive performance compared to conventional office environments. Allen recalled releasing the study at Greenbuild and promoting it globally to make the findings more relatable and impactful.
Allen also advised on indoor air quality systems at JPMorgan’s new headquarters in New York City, featuring enhanced ventilation, filtration, and real-time monitoring in line with WELL recommendations. JPMorgan adopted many of these measures more than a decade ago, despite skepticism at the time. Today, the improvements deliver significant financial and organizational benefits, including better hiring, retention, and employee productivity.
Recently, Allen’s team has been using artificial intelligence to move from identifying problems to testing solutions. They created a privacy-safe digital model of the U.S. population to identify groups most at risk from poor indoor air. Their findings show that young children in older homes built before the 1970s face the greatest exposure risk due to lead-based paint. The team is also modeling wildfire scenarios to evaluate how better building design could have reduced exposure during the Los Angeles fires.
When asked what will become standard practice in the next decade, Allen predicted widespread adoption of real-time indoor air quality sensors in homes and buildings. He emphasized that monitoring is essential to prevention: “You can’t manage what you don’t measure.”
Allen also shared practical advice for improving indoor air at home, including enhancing ventilation and filtration, reducing exposure to persistent chemicals, and focusing on bedroom air quality, given the time people spend sleeping. He described ventilation and filtration as fundamental pillars of public health.
Ultimately, healthier indoor environments can improve well-being for people everywhere, making better buildings a universal benefit.
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